Probiotics: Harnessing the Power of Good Bacteria

FEBRUARY 13, 2013

Yvette C. Terrie, BS Pharm, RPh

Clinical studies support the use of these supplements to promote health.
Probiotic supplements are commonly used to help maintain digestive balance and support a healthy immune system. Their popularity continues to increase as more new products are brought into the market.

For this reason, pharmacists should be prepared to answer patient questions regarding the selection and proper use of these supplements.

The Food and Agriculture Organization of the United Nations and the World Health Organization have defined probiotics as “live microorganisms which when administered in adequate amounts confer a health benefit on the host.”1 Probiotics are identified by their genus, species, and strain, and a variety of studies have investigated their health benefits.2-6

Probiotic supplements are available in a range of dosage forms, such as capsules, tablets, and powders. Probiotics can also be found in fermented dairy products (ie, yogurt, yogurt drinks, and buttermilk), juices, soy products (ie, beverages and miso), and plant products (ie, sauerkraut). In both probiotic foods and dietary supplements, the bacteria may be naturally present or added during the preparation of the product.4,5

Probiotics must withstand processing, storage, and delivery of the product and survive gastric acidity, bile acid lysis, and pancreatic enzyme digestion.5,7 Furthermore, according to USProbiotics.org, the microbe must be alive when administered, must be documented to have a health benefit, and must be given at levels which demonstrate a health benefit.8

Probiotic use has been linked to actions such as competition with pathogens for the binding sites on intestinal mucosa, reduction of intestinal permeability, changes in the intestinal pH, and direct antimicrobial activity against some pathogens.5

Clinical Studies of Probiotics

The FDA does not currently regulate probiotic products. However, results of various clinical trials indicate that probiotics support general wellness and effectively treat a number of medical conditions that involve alterations in the normal flora of the intestines (ie, antibiotic-associated diarrhea/Clostridium difficile–associated diarrhea, traveler’s diarrhea, and infectious diarrhea) as well as inflammatory and functional bowel conditions.5-7,9 Results of a recently published metaanalysis suggest that patients at risk of C difficile–associated diarrhea lowered their infection rate by 66% when prophylactic probiotics were administered.10 Probiotics have also been used to treat atopic dermatitis and allergies.5

A number of ongoing studies are investigating how probiotics produce therapeutic benefits. Results from some of these studies suggest that probiotics may11:

Boost the immune system by producing antibodies for certain viral illnesses

Act as a barrier against bacteria or toxins in the intestinal wall

Produce antibodies that may prevent infections

Some studies suggest that using probiotics may decrease the adverse effects often associated with the treatment of Helicobacter pylori infection as well.12

Results from a study released in November 2012 by the American Heart Association reported that 2 daily doses of a probiotic decreased low-density lipoprotein cholesterol and total cholesterol in some patients with hyperlipidemia.13 Another study published in December 2012 reported that the use of probiotics during pregnancy may help prevent infants from getting eczema.14

Probiotic Supplements

Probiotic supplements may contain 1 or more different species from genera including Lactobacillus, Bifidobacterium, and Saccharomyces.5,15 Within the genus Lactobacillus, L reuteri is the most prevalent strain found in the human body.5 Supplements currently on the market may contain Lactobacillus rhamnosus GG, reuteri, acidophilus, bulgaricus, and fermentum.5,15 Species of Bifidobacterium found in supplements include B longum, bifidum, breve, infanti, and lactis. S boulardii, which is a yeast, is the only species of Saccharomyces used in dietary supplements.5Lactobacillus and Saccharomyces products are often recommended for antibiotic-associated diarrhea, and L rhamnosus GG is recommended for atopic dermatitis.5

Two of the newest probiotic supplements on the market are Pfizer’s Pro Nutrients Probiotic supplement and Bayer HealthCare’s TruBiotics. Pro Nutrients is available in a powder formulation that can be added to cool foods or beverages. TruBiotics is available in capsule form that should be taken once a day. The capsule can also be opened and sprinkled onto cool food. Other available probiotic supplements are listed in the Table.

Patients electing to use probiotic supplements should be reminded to use products only from reputable companies and to adhere to the manufacturer’s dosage guidelines and directions for use. Pharmacists should advise patients—especially those with other medical conditions or those taking any prescription medications—to seek advice from their primary health care provider before using the supplements to ascertain whether it is appropriate to use them.

Patients with compromised immune systems should be advised not to use probiotics because of the potential for systemic infections.5,15 In addition, women who are pregnant or breast-feeding should be sure to seek advice from their doctors before using probiotic supplements. Clinical results are limited, but there are no reports of harmful results associated with the use of probiotics in late-term pregnancies or in those who are breast-feeding.2 Concurrent administration of probiotic supplements with any antibiotics or antifungal agents is typically not advised, and patients should be instructed to administer these agents at least 2 hours apart.5,15

Probiotic supplements are typically well tolerated, although some patients may experience mild episodes of bloating and flatulence, which tends to decrease with continued use.5 In addition, diarrhea is often reported as a side effect of probiotic supplements in children.5,15 Patients who experience severe episodes of diarrhea or other side effects should be encouraged to seek advice from their primary health care provider. Since some probiotic supplements contain lactose, patients who have milk allergies or who are lactose intolerant should avoid using dairy-based supplements. To minimize side effects, the supplements should be taken with cool or room temperature food or drink at the same time each day.

Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.References:

Joint FAO/WHO Working Group on Drafting Guidelines for the Evaluation of Probiotics in Food. Guidelines for the evaluation of probiotics in food. ftp://ftp.fao.org/es/esn/food/wgreport2.pdf. Accessed January 15, 2013.

Probiotics: a consumer guide for making smart choices. International Scientific Association for Probiotics and Prebiotics website. www.isapp.net/docs/Consumer_Guidelines-probiotic.pdf. Accessed January 2, 2013.